This invention relates to something to inflate and expand an airbag of an automobile and, more particularly, to a gas generator capable of controlling an extensive form of the airbag.
In order to protect riders in an automobile from collision, the gas generator to immediately expand and inflate the airbag is built in an airbag module fitted in a steering wheel and an instrument panel. The gas generator is operated under control of collision detection signals from a collision sensor detecting a collision, to produce a large amount of high temperature gas instantaneously.
One typical example of the gas generator to inflate and expand the airbag is shown in FIG. 16. As illustrated, the gas generator has a housing 100 having an annular. enclosed space formed by the double cylinder structure of inner and outer cylinders of upper and lower lidded containers 101, 102 which are put in abutment with and frictional press-contact with each other. In the enclosed space of the housing 100, gas generating agents 103 and a cylindrical filtering member 104 are contained in order from the inner cylinder toward the radial outside. Arranged in the inner cylinder are an igniter 105 that is ignited under control of collision detection signals from the collision sensor and an inflammation agent 106 that is ignited by ignition of the igniter 105.
In this gas generator, the inflammation agent 106 is ignited by ignition of the igniter 105 under control of the collision detection signals from the collision sensor and, further, flame of the inflammation agent 106 is spurted into the enclosed space through a flame guidable aperture 107 of the inner cylinder, whereby the gas generating agents 103 are ignited and burnt to thereby produce a large amount of high temperature gas instantaneously. The large amount of temperature gas enters the filtering member 104 for slag collection and cooling of the gas thereat and thereafter is discharged from a number of gas discharging holes 101a of the upper container 101 into the airbag, so as to inflate and expand the airbag rapidly.
With the conventional gas generator, regardless of the patterns of automobile collision (low-speed collision, high-speed collision, etc.) and seating position of a rider (a normal seat position, an abnormal seat position, such as a stoop-shouldered position, etc.), the igniter is ignited under control of the collision detection signals from the collision sensor to thereby produce a large amount of gas instantaneously to inflate and expand the airbag rapidly. This sometimes provides the disadvantage that when the rider takes a seat position immediately behind the steering wheel or the instrument panel or when the automobile collides at low speed, the rapidly inflating airbag gives a shock to the rider (punching phenomenon), rather than fulfills its intended function to protect the rider.
It is object of the present invention to provide a gas generator that can controllably allow the airbag to inflate and expand slowly at an initial stage of the inflation and thereafter inflate and expand rapidly so that the intended function of the airbag.can be fulfilled.
In the first invention, an enclosed space of a housing is partitioned into a plurality of combustion chambers, and gas generating agents, a filtering member and an igniter are arranged in the combustion chambers, respectively.
This enables the gas discharged into the airbag to be controlled by operating the igniters with time difference, and as such can achieve a multistage control of expansion of the airbag.
In addition, in the first invention, the combustion chambers are communicated to each other. This can allow the combustion of the gas generating agents in the combustion chambers to be effected with a total volume of the housing (enclosed space). Thus, when the igniters are operated with time difference, the airbag can be inflated and expanded moderately by a small amount of gas that is generated in the single combustion chamber and is suppressed in pressure rise characteristic in the initial stage of expansion and thereafter can be inflated and expanded rapidly by the addition of the gas generated in the respective combustion chambers and controlled to a specified gas pressure. characteristic and maximum pressure.
As a result of this, the rider is prevented from being given the shock by the airbag inflated and expanded rapidly in the initial expansion stage (punching phenomenon) and thus the air can fulfill its intended function to protect the rider.
In the second invention, an enclosed space of a housing is partitioned into two combustion chambers by a partition member, and gas generating agents, a filtering member and an igniter are arranged in the combustion chambers, respectively.
This enables the gas discharged into the airbag to be controlled by operating the two igniters with time difference, and as such can achieve a two-stage control of expansion of the airbag.
In addition, in the second invention, the combustion chambers are communicated to each other. This can allow the amount of gas and pressure rise characteristic of the expansion of the airbag to be controlled, to inflate and expand the airbag, as is the case with the first invention.
In the third invention, a housing is formed into a short, cylindrical shape; an enclosed space in the housing is partitioned into two combustion chambers by a partition member; and gas generating agents and a filtering member are arranged in the combustion chambers, respectively. Also, a long, cylindrical, inner casing and a short, cylindrical, inner casing are extended into the combustion chambers, respectively, and igniters are arranged in the inner casings, respectively.
This enables the gas discharged into the airbag to be controlled by operating the two igniters with time difference, and as such can achieve a two-stage control of expansion of the airbag. Besides, the gas generating agents in the combustion chambers can be burnt with a simple structure that the igniters are arranged in their respective inner casings. In addition, since the housing is formed into a short, cylindrical shape, the gas generator is optimum to inflate and expand the airbag for driver seat.
In addition, in the third invention, the combustion chambers are communicated to each other. This can allow the amount of gas and pressure rise characteristic of the expansion of the airbag to be controlled, to inflate and expand the airbag, as is the case with the first invention.
In the fourth invention, the housing is formed into a short, cylindrical shape; the enclosed space in the housing is partitioned into two combustion chambers by the partition member; and the gas generating agents and the filtering member are arranged in the combustion chambers, respectively. Also, the long, cylindrical, inner casing and the short, cylindrical, inner casing are extended into the combustion chambers, respectively; upper and lower lids of the housing are joined via the long, cylindrical, inner casing; and the igniters are arranged in the inner casings, respectively.
This enables the gas discharged into the airbag to be controlled by operating the two igniters with time difference, and as such can achieve a two-stage control of expansion of the airbag. Besides, the gas generating agents in the combustion chambers can be burnt with a simple structure that the igniters are arranged in their respective inner casings. Since the structure of the lids of the housing being joined via the long, cylindrical casing enables structural strength of the housing to increase, it can suitably be used for a large-sized gas generator to produce a large amount of gases and for non-azide-base generating agents to generate high pressure gas. In addition, since the housing is formed into the short, cylindrical shape, the gas generator is optimum to inflate and expand the airbag for driver seat.
In addition, in the fourth invention, the combustion chambers are communicated to each other. This can allow the amount of gas and pressure rise characteristic of the expansion of the airbag to be controlled, to inflate and expand the airbag, as is the case with the first invention.
In the fifth invention, the housing is formed into a short, cylindrical shape; the combustion space in the housing is partitioned into two combustion chambers by the partition member; and the gas generating agents and the filtering member are arranged in the combustion chambers, respectively. Also, the long, cylindrical, inner casing and the short, cylindrical, inner casing are extended into the combustion chambers, respectively; and the igniters are arranged in the inner casings, respectively.
This enables the gas discharged into the airbag to be controlled by operating the two igniters with time difference, and as such can achieve a two-stage control of expansion of the airbag. Besides, the gas generating agents in the combustion chambers can be burnt with a simple structure that the igniters are arranged in their respective inner casings. In addition, since the housing is formed into the short, cylindrical shape, the gas generator is optimum to inflate and expand the airbag for driver seat.
In addition, in the fifth invention, the enclosed space in the housing is partitioned into the gas passage space and the combustion spaces by an inner cylindrical member, whereby the combustion chambers are communicated to each other via the gas passage space. This enables the combustion chambers to be communicated to each other with a simple structure of simply adding the inner cylindrical member and also can allow the amount of gas and pressure rise characteristic of the expansion of the airbag to be controlled, to inflate and expand the airbag, as is the case with the first invention.
In the sixth invention, a housing is formed into a short, cylindrical shape; an enclosed space in the housing is partitioned into two combustion chambers by a partition member; and gas generating agents and a filtering member are arranged in the combustion chambers, respectively. Also, a long, cylindrical, inner casing and a short, cylindrical, inner casing are extended into the combustion chambers, respectively; upper and lower lids of the housing are joined via the long, cylindrical, inner casing; and igniters are arranged in the inner casings, respectively.
This enables the gas discharged into the airbag to be controlled by operating the two igniters with time difference, and as such can achieve a two-stage control of expansion of the airbag. Besides, the gas generating agents in the combustion chambers can be burnt with a simple structure that the igniters are arranged in their respective inner casings. Since the structure of the lids of the housing being joined via the long, cylindrical casing enables structural strength of the housing to increase, it can suitably be used for a large-sized gas generator to produce a large amount of gases and for non-azide-base generating agents to generate high pressure gas. In addition, since the housing is formed into the short, cylindrical shape, the gas generator is optimum to inflate and expand the airbag for driver seat.
In addition, in the sixth invention, the enclosed space in the housing is partitioned into the gas passage space and the combustion spaces by an inner cylindrical member, whereby the combustion chambers are communicated to each other via the gas passage space. This enables the combustion chambers to be communicated to each other with a simple structure of simply adding the inner cylindrical member and also can allow the amount of gas and pressure rise characteristic of the expansion of the airbag to be controlled, to inflate and expand the airbag, as is the case with the first invention.
In the seventh invention, the housing is formed into a short, cylindrical shape; a combustion space in the housing is partitioned into two combustion chambers by the partition member; and the gas generating agents and the filtering member are arranged in the combustion chambers, respectively. Also, the long, cylindrical, inner casing and the short, cylindrical, inner casing are extended into the combustion chambers, respectively; and the igniters are arranged in the inner casings, respectively.
This enables the gas discharged into the airbag to be controlled by operating the two igniters with time difference, and as such can achieve a two-stage control of expansion of the airbag. Besides, the gas generating agents in the combustion chambers can be burnt with a simple structure that the igniters are arranged in their respective inner casings. In addition, since the housing is formed into the short, cylindrical shape, the gas generator is optimum to inflate and expand the airbag for driver seat.
In addition, in the seventh invention, the enclosed space in the housing is partitioned into the gas passage space and the combustion spaces by an inner cylindrical member and a filtering member, whereby the combustion chambers are communicated to each other via the gas passage space and the filtering member. This enables the combustion chambers to be communicated to each other with a simple structure of simply adding the inner cylindrical member combined with the filtering member and also can allow the amount of gas and pressure rise characteristic of the expansion of the airbag to be controlled, to inflate and expand the airbag, as is the case with the first invention.
In the eighth invention, a housing is formed into a short, cylindrical shape; an enclosed space in the housing is partitioned into two combustion chambers by a partition member; and gas generating agents and a filtering member are arranged in the combustion chambers, respectively. Also, a long, cylindrical, inner casing and a short, cylindrical, inner casing are extended into the combustion chambers, respectively; upper and lower lids of the housing are joined via the long, cylindrical, inner casing; and igniters are arranged in the inner casings, respectively.
This enables the gas discharged into the airbag to be controlled by operating the two igniters with time difference, and as such can achieve a two-stage control of expansion of the airbag. Besides, the gas generating agents in the combustion chambers can be burnt with a simple structure that the igniters are arranged in their respective inner casings. Since the structure of the lids of the housing being joined via the long, cylindrical casing enables structural strength of the housing to increase, it can suitably be used for a large-sized gas generator to produce a large amount of gases and for non-azide-base generating agents to generate high pressure gas. In addition, since the housing is formed into the short, cylindrical shape, the gas generator is optimum to inflate and expand the airbag for driver seat.
In addition, in the eighth invention, the enclosed space in the housing is partitioned into the gas passage space and the combustion spaces by an inner cylindrical member and a filtering member, whereby the combustion chambers are communicated to each other via the gas passage space and the filtering member. This enables the combustion chambers to be communicated to each other with a simple structure of simply adding the inner cylindrical member combined with the filtering member and also can allow the amount of gas and pressure rise characteristic of the expansion of the airbag to be controlled, to inflate and expand the airbag, as is the case with the first invention.
In the tenth invention, a housing is formed into a short, cylindrical shape; an enclosed space in the housing is partitioned into two combustion chambers by a partition member; and gas generating agents and a filtering member are arranged in the combustion chambers, respectively. Also, a long, cylindrical, inner casing and a short, cylindrical, inner casing are extended into the combustion chambers, respectively; and igniters are arranged in the inner casings, respectively.
This enables the gas discharged into the airbag to be controlled by operating the two igniters with time difference, and as such can achieve a two-stage control of expansion of the airbag. Besides, the gas generating agents in the combustion chambers can be burnt with a simple structure that the igniters are arranged in their respective inner casings. In addition, since the housing is formed into the short, cylindrical shape, the gas generator is optimum to inflate and expand the airbag for driver seat.
In addition, in the ninth invention, the combustion chambers are communicated to each other through gas passing holes in the partition member. This enables the combustion chambers to be communicated to each other with a simple structure of simply forming the gas passing holes in the partition member and also can allow the amount of gas and pressure rise characteristic of the expansion of the airbag to be controlled, to inflate and expand the airbag, as is the case with the first invention.
In the tenth invention, the housing is formed into a short, cylindrical shape; the enclosed space in the housing is partitioned into the two combustion chambers by the partition member; and the gas generating agents and the filtering member are arranged in the combustion chambers, respectively. Also, the long, cylindrical, inner casing and the short, cylindrical, inner casing are extended into the combustion chambers, respectively; upper and lower lids of the housing are joined via the long, cylindrical, inner casing; and igniters are arranged in the inner casings, respectively.
This enables the gas discharged into the airbag to be controlled by operating the two igniters with time difference, and as such can achieve a two-stage control of expansion of the airbag. Besides, the gas generating agents in the combustion chambers can be burnt with a simple structure that the igniters are arranged in their respective inner casings. Since the joining structure via the long, cylindrical casing enables structural strength of the housing to increase, it can suitably be used for a large-sized gas generator to produce a large amount of gases and for non-azide-base generating agents to generate high pressure gas. In addition, since the housing is formed into the short, cylindrical shape, the gas generator is optimum to inflate and expand the airbag for driver seat.
In addition, in the tenth invention, the combustion chambers are communicated to each other through the gas passing holes in the partition member. This enables the combustion chambers to be communicated to each other with a simple structure of simply forming the gas passing holes in the partition member and also can allow the amount of gas and pressure rise characteristic of the expansion of the airbag to be controlled, to inflate and expand the airbag, as is the case with the first invention.
In the eleventh invention, the housing is formed into a long, cylindrical shape; the enclosed space in the housing is partitioned into the two combustion chambers; and the gas generating agents and the filtering member are arranged in the combustion chambers, respectively. Also, the igniters are respectively arranged at both ends of the housing.
This enables the gas discharged into the airbag to be controlled by operating the two igniters with time difference, and as such can achieve a two-stage control of expansion of the airbag. Besides, since the housing is formed into the long, cylindrical shape, the gas generator is optimum to inflate and expand the airbag for passenger seat or passenger-side collision.
In addition, in the eleventh invention, the combustion chambers are communicated to each other. This can allow the amount of gas and pressure rise characteristic of the expansion of the airbag to be controlled, to inflate and expand the airbag, as is the case with the first invention.
In addition, the eleventh invention can adopt any of the system that the enclosed space in the housing is partitioned into the two combustion chambers by the partition member, whereby the combustion chambers are communicated to each other through the gas passing holes in the partition member; the system that the enclosed space in the housing is partitioned into the gas passage space and the combustion space by the inner cylindrical member and also the combustion space is partitioned into two combustion chambers.by the partition member, whereby the combustion chambers are communicated to each other through the gas passage space; and the system that the enclosed space in the housing is partitioned into the gas passage space and the combustion space by the inner cylindrical member and the filtering member and also the combustion space is partitioned into two combustion chambers by the partition member, whereby the combustion chambers are communicated to each other through the gas passage space and the filtering member.
In the third through tenth inventions, a convex portion is formed in the partition member, for containing the igniter therein. This enables the igniter to be easily contained in the short, cylindrical, inner casing. Also, the third through tenth inventions adopt the structure that the partition member is positioned in abutment with a step portion of the long, cylindrical, inner casing. This enables the two combustion chambers to be partitioned with a simple structure and also enables the proportion of volume of the two combustion chambers to vary with ease by adjusting the step portion.
Further, in the second through eleventh invention, a cushioning member is arranged in the partition member, for suppressing the transmission of heat of combustion. This enables the transmission of the heat of combustion generated in one of the combustion chambers to be blocked off, which in turn enables the ignition to be surely adjustably controlled by the respective igniters when the gas generating agents in the two combustion chambers are ignited with time difference.
In the fifth through eighth invention and the eleventh invention, the inner cylindrical member is formed of an expanded metal. The expanded metal has a number of gas passage holes that are. projected out toward inside and outside thereof to communicate the inside and the outside to each other, such that the expanded metal layer itself forms the gas passage space. This enables the inner cylindrical member, the outer casing and the filtering member to be disposed in close contact with each other to facilitate the positioning and arrangement of these members.
Further, in the first through eleventh inventions, the filtering member is formed of a metal wire of stocking stitch or a metal wire rod of a crimp mesh. This enables the filtering member to be produced at low costs.